1. Technical Field
The present invention relates to dihydrate and anhydrous crystalline forms of 5,11-dihydro-11-ethyl-5-methyl-8-{2-{(1-oxido-4-quinolinyl)oxy}ethyl}-6H-dipyrido[3,2-b:2′,3′-e] [1,4]diazepin-6-one.
2. Background Information
5,11-Dihydro-11-ethyl-5-methyl-8-{2-{(1-oxido-4-quinolinyl)oxy}ethyl}-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one is a non-nucleoside HIV-1 reverse transcriptase inhibitor. Its chemical structure is as depicted below.

The synthesis of 5,11-dihydro-11-ethyl-5-methyl-8-{2-{(1-oxido-4-quinolinyl)oxy}ethyl}-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one, its use for the treatment of HIV infection, and pharmaceutical compositions comprising this substance and suitable for this use are described in U.S. Pat. No. 6,420,359 and the corresponding WO0196338.